The oldest, and one of the most beloved, polar bears in the United States died on Friday at the age of 34.

The Philadelphia Zoo announced in a Facebook message that Klondike was euthanized following a "recent and substantial decline in her medical condition." According to the statement, Klondike had trouble standing and walking despite treatment.

"There was no significant improvement in her condition, and given her advanced age and poor prognosis, zoo staff decided that the best decision would be to humanely euthanize her," the statement reads. "Given her advanced age and poor prognosis for return to a good quality of life, zoo staff decided that the best decision would be to humanely euthanize her."

Klondike was born in November 1980 in New York's Bronx Zoo. A year later, the female bear was transported to the Philadelphia Zoo, where she became one of the biggest attractions at the park.

In a statement, General Curator Kevin Murphy said that Klondike was also noted for being an important "ambassador to wild polar bears, who are increasingly threatened by climate change and resulting shrinkage of polar ice," reports WPVI-TV. He added, "We hope she has inspired many to make commitments in their daily lives to reduce energy and water use, which will contribute to efforts to slow climate change."

Zoo officials noted that Klondike exceeded the typical lifespan for polar bears, since most in captivity usually live about 30 years, while those in the wild live to be about 20 years old.

The zoo's remaining polar bear, Coldilocks, has now become the nation's oldest polar bear at the age of 34 years old.

The oldest living polar in the world, Debby, died at age 42 in 2008 at Canada's Assiniboine Park Zoo, according to Reuters.